半刚性基层的材料特性

Material Characteristics of Semi-rigid Base

从强度、温度收缩和干燥收缩、抗冲刷以及疲劳4个方面论述了半刚性基层材料的特性,指出:半刚性基层材料的强度可以根据路面结构要求在一个很宽的值域内设计;半刚性基层材料的强度获得不仅要靠一定剂量的结合料,更要靠良好级配的集料;及时的保湿养生可以避免半刚性基层材料的干燥收缩裂缝;控制细料含量可以显著减小半刚性基层材料的温度收缩裂缝;通过减少细料含量、增加结合强度以及增大空隙率等合适的材料组成设计,可以显著地提高半刚性基层材料的抗冲刷性能;半刚性基层材料是应力敏感性材料,将半刚性基层放在路面中合适的层位,可以使其具有更长的疲劳寿命。

The characteristics of semi rigid base material were researched in four strength, temperature shrinkage and drying shrinkage, erosion resistance and aspects： fatigue. Conclusions are as following： strength of semi-rigid base material can be designed in a quite broad range by the requirement of pavement structure and the strength is obtained not only by the binder but also by aggregations properly designed; cracks caused by drying shrinkage are avoidable by well-timed curing and cracks caused by temperature shrinkage can be reduced evidently by controlling the content of fine aggregate; anti-erosion performance of semi-rigid material can be obviously improved by designing proper material composition, such as reducing the content of fine aggregate, improving the strength of binders and increasing the void of mixtures; semi-rigid base material is stress sensitive material and a pavement will have a longer fatigue life if semi-rigid base can be placed in proper position of pavement.